From a poor family in Sestao, Biscay, Venancio started working at a young age in the Altos Hornos de Vizcaya factory.

[1] After starting out at SD Erandio Club[2] he signed with Athletic Bilbao in early 1945 for 25.000 pesetas, but appeared sparingly in his first seasons, being loaned to Barakaldo CF from Segunda División.

He finished the campaign with a further five in only six appearances, and went on to be part of one of the most legendary attacking lines in the club's history alongside Agustín Gaínza, Rafael Iriondo, José Luis Panizo and Telmo Zarra, winning four titles which included three Copa del Generalísimo.

[1] Venancio left the San Mamés Stadium in 1955, aged 34, retiring after a spell in the second tier with former team Barakaldo.

[4] On 6 January 1954, Venancio scored the last of his four goals for the country to help to a 4–1 defeat of Turkey for the 1954 FIFA World Cup qualifiers, but the opposition would eventually reach the finals in Switzerland after a drawing of lots.